I first saw it here - http://www.examiner.com/article/how-can-necromancer-games-release-5e-d-d-material-without-a-license via G+

Original blog source here - http://froggodgames.org/blog/about-legal-questions

(Emphasis mine)

Quote from: Matt FinchAmurayi, you're asking if this project is "legally approved by WotC." I could give the surface answer and say, "Yes, it's done under a license (the OGL) that WotC approved long ago." But I think your real question is whether WotC has taken a look at a specific proposal from us, and said, "Go for it. Pre-approved." The answer to that question is, "they haven't, and we haven't asked them to, because to the best of my knowledge they haven't ever done specific project-approvals like that with third-party publishers." I think you're also asking what guarantees you have that the material will be compatible. Once again, the surface answer is: "No more guarantee than people got with similar (OGL) products during the old days of d20-style publishing." As then, you have to look at the people involved, their reputations, past products, etc., to figure out what kind of job they are likely to do.  In this case, because there's not a specific license addressing our use of 5th Edition material, Steve Winter and I will make some changes to copyrightable names/labels when it's required to identify an underlying rule. One example being "witch bolt" to "witch-fire bolt." One benefit to working with lawyers on this is that it allows us not to "overdo" changes. If it needs to be changed, we'll change it, and do so as little as possible. That's one of the ways attorneys earn their money. Will it read exactly like it came from WotC? Nope, there will be a number of tweaks like the one above, which people have already seen in our free Wizards Amulet module. We are an intellectual property company; we absolutely respect intellectual property rights. But ultimately, this isn't an issue of "legal approval." There's not a single rubber stamp that says, "Approved." In actuality, there's a whole bundle of things that one can or can't do, depending on what you have licenses for and what you've produced yourself. In the case of the OGL, we can refer to material from the System Reference Document, but cannot indicate compatibility with a trademark (which is why we say the material will be compatible with "5th Edition"). We're not hiding anything or being evasive with that, it's simply what the license requires. There will be some slightly changed names of things, but we're all smart enough to figure those out, even if they get a bit more changed than "witch bolt" to "witch-fire bolt." If you need absolute one-to-one correspondence of all the game terms in order to enjoy the product, you will have to wait until WotC creates a third-party license to use 5th Edition terminology, or stick to WotC products exclusively. For some people, that's absolutely an issue, and we understand and empathize with it. But WotC has the right to set the rules for most of this material, and we are following those rules.  I hope this answers the question.

They're moving ahead with their own line of products under the (3.5) OGL by keeping things compatible if not 'blessed off', via name-changes, etc.

It's an interesting approach.  But what about the new mechanics, e.g. Advantage?  Can you, in your 'toeing-the-legal-line' version of a 'Creature Catalog' have an ability that gives 'Advantage'?  Or would it just say 'rolls twice and takes the best'?  Or maybe they flatten it to a +5?

What other things might get sticky?

Well, they wouldn't move forward with the "5th Edition" line unless they were sure they were covered, and they're hinting they have the legal ability to not be deterred by a "go away" lawsuit.

Roll X Keep Y is hardly a new mechanic, but the name "Roll and Keep System" is trademarked by AEG.

The statement sounds a little overconfident and aggressive, I think he wasn't talking to the OP in that statement but WotC, basically saying "if you don't let us license shit, we're gonna publish for it under the free license anyway".

The thing that will get sticky is, I don't think they're going to exactly mimic every single power and just rename it, so there will be changes.  That would cause blood vessels to burst in the rules mastery crowd, but if FG decides to publish everything 3 times, PF, SW and 5th, then the rules mastery guys will get the PF version anyway.

Just had a thought - what if 'witch-fire bolt' or whatever FGG labels they pick become like a new thieves cant for 3pp?

See, the OGL is contagious, or can be, so long as you cite your sources and follow the other rules.

Well if "Witch-Fire Bolt" isn't in the SRD, then it's a "Frog God Invention" and they don't have to declare it open if they don't want to.  In fact, if you look closely, a lot of the 3PP OGL people lock up way more then just IP names.

They could become the lingua franca of non-licensed 5e, but WotC would have get involved before that point I think just to prevent making themselves another competitor that they know can write better then they can.

Some companies (including Necromancer) were very good at locking things up in their products by using vague language about what was open and what wasn't. Which is arguably contrary to the OGL, but who is going sue, exactly? The OGL happened so long ago (in corporation time) no one at Hasbro probably even knows what it is.

For instance, this is from one of their modules

QuoteX is written under version 1.0a of the Open Game License. As of yet, none of the material first appearing in X is considered Open Game Content.

OTOH, the Wizard's Amulet was pretty open.

And actually some of the new 5e mechanics showed up in other games first.

Advantage/Disadvantage, for instance, actually is in Blood & Treasure. It's different, it only is a +2 bonus, but the concept existed in an OGL before 5e came out. The author was amused when it showed up in 5e.

But the mechanics of roll two d20s is in a number of Pathfinder rules.